Authors:

It is most important in creative science not to give up. If you are an optimist you will be willing to "try" more than if you are a pessimist.

"Adventures of a Mathematician". Book by Stanislaw Ulam, 3rd edition. Chapter 3: "Travels Abroad", p. 55, 1991.
It is most important in creative science not to give up. If you are an optimist you will be willing to try more than if you are a pessimist.